Transition metal complex directed synthesis of porous cationic polymers for efficient CO2 capture and conversion

Abstract The advent of porous polymers capable of both CO 2 capture and conversion is an emerging research area to tackle ever-increasing CO 2 emissions into the atmosphere and also to use CO 2 as a sustainable C1 source. Porous cationic polymers, which are analogous to zeolites, with exchangeable counteranions offer ideal platform for the simultaneous capture and conversion of CO 2 . Here, we report on the porous cationic polymers (Ru-PCPs) with increased number of charges synthesized through condensation reaction between tris (1,10-phenanthroline-5,6-dione)Ru(II) dichloride and ortho -aromatic amines in AlCl 3 at 400 °C. Ru-PCPs exhibited surface areas up to 526 m 2  g −1 and CO 2 uptake capacities as high as 3.76 mmol g −1 , which is among the highest reported to date for porous cationic polymers. The high CO 2 -philicity of Ru-PCPs originating from the presence of multiple charges and nitrogen sites coupled with the nucleophilic Cl − anions rendered Ru-PCPs as highly efficient heterogeneous catalysts for the conversion of CO 2 and propylene oxide to propylene carbonate through atom economy reaction. Notably, unlike previously reported porous cationic organocatalysts which require CO 2 pressures of 10–30 bar, Ru-PCPs were shown to operate efficiently even under atmospheric pressure of CO 2 mainly arising from the increased number of charges and counteranions.